Geared hydraulic letoff for looms



Dec. 15, 1942. A. J. HERARD, JR

GEARED HYDRAULIC LET- OFF FOR LOOMS Filed June 4, 1942 Ancmaaw JI Hammofll'a 64.4 7. #w A'T-roRNEY Patented Dec. 15, 1942 GEARELD HYDRAULIC LETOFF FOR LOOMS Archibald J. Herard, Jr., Worcester, Mass assignor to Crompton & Knowles Loom Works, Worcester, Mass, a corporation of Massachusetts Application June 4, 1942, Serial No. 445,789 14 Claims. (01. 139-109) This invention relates to improvements in letofi mechanisms for looms and it isthe general object of the invention to provide a hydraulically operating mechanism geared to the warp beam and controlled to lock and release the warp beam alternately depending upon the demands for warp made by the weaving operation.

In the let-off mechanism set forth hereinafter I provide a whip roll which is moved forwardly by consumption of the warp when a warp beam is held against rotation, and provide means such as a weight to move the whip roll rearwardly to compensate for slackness of the warp when the beam rotates. The geared mechanism referred to includes a gear secured to the warp beam and meshing with a pinion which controls the rotation of the gear and beam. It is an important object of my present invention to provide hydraulically controlled brake means to hold the pinion against rotation to prevent turning of the gear and warp beam when there is ample warp for the weaving operation, and release the pinion to permit Warp tension to turn the beam and pinion when the warp has been consumed to a given minimum.

It is a' further object of my present invention to provide a convenient connection between the warp beam and the hydraulically operating brake mechanism so constructed as to facilitate removal of the warp beam without disturbing the brake mechanism. This result I accomplish by connecting the beam and brake mechanism by means of meshing gears which can roll with respect to each other when the beam is being removed.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawing, wherein a convenient embodiment of my invention is set forth,

Fig. l is a rear elevation of one end of a loom showing my improved let-off mechanism applied thereto,

Fig. 2 is a side elevation, onfa slightly reduced scale, looking in the direction of arrow 2, Fig. 1,

Fig. 3 is a plan view looking in the direction of arrow 3, Fig. 1, showing both sides of the loom and the connections between the whip roll and my invention,

Fig. 4 is a vertical section on line -d of Fig. 1, I

Fig. 5 is an enlarged horizontal section on line 5-5, Fig. 4, through the brake cylinder of the hydraulic system,

Fig. 6 is an enlarged vertical section on line 6.B of Fig. 3 through the master cylinder of the hydraulic system, and

Fig. 7 is a view similar to a portion of Fig. 2 but showing the whip roll locked in a. position which will facilitate removal of the warp beam from theloom.

Referring to the drawing, I have shown the rear part of the loom frame l0 provided with spaced bearings ll, one being shown in Fig- 2, to receive the shaft I2 of a warp beam B. The beam comprises a barrel 13 having warp spacing heads one, of which is shown at M in Fig. 1. Each bearing ii is provided with a cap l5 pivoted at [6 to its bearing II and held in position by a bolt I! which canbe released to permit the cap to swing upwardlywhen it is desired to remove the beam from the loom.

Each side of the loom is provided with a bracket 20 on which an upright lever 21 is pivoted as at 22. The levers 2i have rotatably mounted thereon the whip roll 23 over which the warp W passes from the warp beam forwardly to the weaving instrumentalities not shown. Each bracket 20 is provided with a stand 25 on which a horizontal lever 26 is pivoted at 21. Each lever extends forwardly to be pivoted at-28 to a rod 29 which extends across the loom. Each lever 26 also has a lateral arm 30 positioned for engagement with the corresponding lever 2|. A small stand 35 is secured to the right hand bracket 20 and haspivoted thereto at 36 a lever 37 from which hangs a rod 38 carrying weights 39. A link 40 is pivoted at M to the lever 31 and is connected at 42 to the rod 29, see Fig. 3.

'It is to be understood that whenever the warp beam B isheld' againstrotation consumption of the warp W results in forward motion, or movement to the right in Fig. 2, of the whip roll 23 which acts through levers ii and 25 to cause upward movement of theweights 39. As soon as the warp beam is released to rotate the weights 39 exert a rearward pressureron levers 2| and the whip roll will move rearwardly, in a left hand direction: asviewed in Fig. 2, to, tighten any warp which may have been unwound from the beamB. 4 i

The matter thus far described of itself forms no part of my present invention and may be made as set forth in prior-patent to Payne No. 2,184,059 to which reference may be had for a further understanding of the matter already described. a

In carrying my present invention into effect .I provide means for controlling the :periods during which the warp beam is free to rotate. A gear 45 is secured to one end of shaft l2 to rotate with the warp beam. As shown in Fig. 1 I may form the gear 45 with a lug 45 which projects into a corresponding notch in the barrel l3, and the gear may be held against the adjacent end of the barrel by means of bolts 41. The gear 45 meshes with a pinion 59 on a shaft the left end of which as viewed in Fig. 1 turns in a bearing 52 fast with respect to the loom frame and the right end of which turns in a bearing 53 also secured to the loom frame. A shell 55 has a hub 56 surrounding the stub shaft 5| and a. key 57 causes a pinion 50 and shell 55 to rotate with the shaft 5|. Set screws 58 may be used to hold the pinion and shell in proper longitudinal position on shaft 5|.

The shell 55 is provided with a drum 60 having an internal brake surface 6| provided for engagement with right and left hand brake shoes 62 and 63. respectively, as seen in Fig. 4. These shoes are pivoted on studs 65 which are carried by a disk 66 bolted at 61 to the bearing 53. If desired a link 68 may connect the bolts 65 to brace them.

Secured to the disk 65 is a hydraulic brake cylinder having pistons 1|, see Fig. 5, one piston for each of the brake shoes. A hydraulic tube 12 is connected to the interior of the cylinder- 10 between the pistons, and a spring 73 shown in Fig. 4 is connected to the shoes and tends to move the latter away from the braking surface 6| and hold the upper ends of the brake shoes against their respective pistons to tend to move the latter toward each other and the longitudinal center of the cylinder 19.

The right hand bracket has fixedly mounted thereon a hydraulic master cylinder 80 the foot 8| of which is bolted to the bracket 20. The tube 12 connects to the right hand end of the cylinder 89 as shown in Figs. 3 and 6, While the left hand end of the cylinder has projecting therefrom a stem 82 positioned for engagement with the right hand lever 26. A piston 83 in cylinder 80 is movable by stem 82 toward tube I2.

The hydraulic cylinders 10 and 89 may be of any approved form and may be made as set forth in detail in my co-pending application Serial No. 414,729. It is thought suflicient for present purposes to state that when the stem or ii piston 82 is moved to the right as viewed in Fig. 3 fluid in cylinder 80 is placed under pressure which is communicated through the tube 12 to the cylinder Hi to spread the pistons apart and thereby cause the brake shoes to move against the brake surface 6|. When the stem 82 is free to move to the left the spring 13 will move the shoes away from the brake surface and will cause the pistons H to approach each other with resultant upward movement of the fluid in the system to the cylinder 89.

Assuming that the whip roll is in its rearmost position, the levers will be moved to their extreme right hand position as viewed in Fig. 3 by weight 39 with the right hand lever 26 exerting pressure on the stem 82. Under these conditions the pressure within the hydraulic system will be sufficiently high to spread the pistons TI and cause the brake shoes to hold the drum 60 and thereby the pinion 5|] against rotation. The gear is therefore held against turning and the warp beam is held stationary. As weaving continues the warp is consumed and the' whip roll 23 moves forwardly or to the right, but in doing so will move the levers 2| forwardly to cause a counter-clockwise turning of levers 26 as viewed in Fig. 3. The right hand lever 26 will eventually move away from the stem 82 thereby relieving hydraulic pressure within the system and permitting spring 13 to draw the brake shoes away from the surface 6|. The drum 69 and pinion are now free to turn and the tension in the warp causes a partial rotation of the warp beam to pay off additional warp. As soon as slackness in the warp develops the weight 39 will move the whip roll rearwardly until the right hand lever 26 again engages the stem 82 to lock the pinion against turning by the brake shoes as already described. This alternate tightening and loosening of the pinion goes on continually during weaving and is accompanied by oscillation of the whip roll 23 between back and front positions.

When the warp is exhausted and it is desired to remove the empty beam the bearing caps l5 will be be released as already described and the warp beam removed from the loom by a rearward motion to the left as viewed in Fig. 2. During its removal the gear 45 can remain in mesh with the pinion 50 until the shaft I2 is clear of the bearings, after which the beam may be raised so that the teeth of gear 45 will clear the teeth of pinion 5|), or the beam may be rolled downwardly and rearwardly until the gear moves away from the pinion by a rearward movement into the aisle behind the loom.

In order to prevent the weight 39 from moving the whip roll to a rear position where it may interfere with removal of the beam, I provide a hook 90 pivoted to the right hand bracket 20 and positioned to engage a pin 9| on the adjacent upright lever 2| as suggested in Fig. 2. This hook has two notches 92 and 93 each of which can receive the pin 9|. If it is desired to keep the pinion 5|] locked during removal of the beam the whip roll 23 will be moved to its rearward position and notch 93 engaged with the pin 9|. If, on the other hand, it is desired that the pinion 50 be free to rotate and thereby permit 3 rearward movement of the warp beam without turning thereof notch 92 will be engaged with pin 9| to hold the whip roll in a forward position where the stem 82 will not be engaged by the adjacent levers 26. In both positions of the hook the weight 39 will be supported.

From the foregoing it will be seen that I have provided a simple form of let-off mechanism for looms wherein a gear fast with respect to the warp beam meshes with a pinion rotation of which is controlled by the hydraulically acting brake mechanism. The difference in diameter between the gear 45 and pinion 50 permits the use of smaller hydraulic cylinders than are desirable in my aforesaid copending application. It will also be seen that the warp beam can be removed from the loom without disturbing the brake mechanism and its setting, Furthermore, the hook 90 can be used to lock the whip roll in those positions which will either hold the pinion against rotation or permit turning thereof.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In a'warp let-off mechanism for a loom having a rotatable warp beam provided with a gear held against rotation relatively thereto, a pinion meshing with the gear, brake means for the pinion movable either to holding position to prevent rotation of the pinion and gear or to releasing position to permit rotation of the pinion and gear with the warp beam, a hydraulic system connected to the brake means, mechanism acting normally on the hydraulic system to cause the latter to move the brake means to pinion holding position, and other means to transmit an opposing force to the mechanism derived from the warp as the tension of the latter increases during the weaving operation while the beam is prevented from rotation and cause the mechanism to effect a reduction of fluid pressure within the hydraulic system to a level insufficient to cause the brake means to hold the pinion from rotation.

' 2. In a warp let-01f mechanism for a loom having a rotatable warp beam provided with a gear turning therewith, a pinion meshing with the gear, brake means for the pinion, a hydraulic system connected to the brake means to control the amount of braking force exerted by said braking means on said pinion, warp engaging means operated by a force derived from the Warp as the tension in the latter increases during the weaving operation when the warp beam is prevented from rotating to effect a reduction of fluid pressure within the hydraulic system to a level which permits the pinion and beam geared thereto to turn, and weighted means operative due to slackening of the warp tension due to rotation of the warp beam to move the warp engaging means in a direction to establish fluid pressure within the hydraulic system sufiiciently high to cause the brake means to prevent rotation of the pinion and warp beam.

3. In a warp let-ofi mechanism for a loom having a rotatable warp beam with a gear secured thereto, a pinion meshing with and rotating with the gear, means moved from holding to releasing position by a force derived from the warp when the tension of the latter increases during weaving, provided rotation of the beam is prevented, brake mechanism to control rotation of the pinion, a hydraulic system controlling the brake mechanism andunder control of said means, return mechanism for said means to move the latter from releasing to holding position when tension in the warp is reduced, said means when in holding position maintaining sufficient pressure within said hydraulic system to cause the brake mechanism to prevent rotation of said pinion and gear, and said means when moving to releasing position reducing the pressure within said hydraulic system to a level insufficient to cause the brake mechanism to prevent rotation of said pinion and gear, whereupon the warp due to the tension thereof causes rotation of the warp beam to reduce the warp tension and the return mechanism moves said means to holding position to reestablish sufficient pressure in said hydraulic system to prevent further rotation of the pinion and gear.

4. In a warp let-off mechanism for a loom having a rotatable warp beam and a gear secured to and turning therewith, a pinion meshing with and rotating with the gear when the beam turns, brake means for the pinion movable either to pinion holding or pinion releasing position, a hydraulic system connected to and controlling the brake means, a whip roll movable forwardly to a given position during the weaving operation by a force derived from the warp when the warp beam is held against rotation, means tending normally to move the whip roll rearwardly to a second given position, and the mechanism to vary the fluid pressure within said hydraulic system, said mechanism being caused by a force deriving from the whip roll when the latter moves forwardly to said first given position to produce a pressure within the system insufficient to cause the brake means to hold said; pinion, and said mechanism efiective when the whip roll moves rearwardly to said second given position to produce .suiflcient pressure within 'saidhydraulic system to cause the brake means to hold the pinion against rotation.

5. In a warp let-off mechanism fora loom having a warp beam provided with a gear rotatable therewith and the loom having a whip roll movable forwardly by the warp during the weaving operation when the warp beam is prevented from rotating, the loom being provided also with return means to move the whip roll rearwardly due to lessening of the warp tension when the beam rotates to feed warp, a pinion s meshing with the gear and turning when the Warp beam rotates and acting through the gear to hold the warp beam stationary when said pinion is prevented fromrotating, brake means for the pinion movable to holding position to prevent rotation of the pinion and beam, release means to move the brake means to releasing position to permit rotation of the pinion when the warp causes rotation of the warp beam, a'member moved by the whip roll from holding to releasing position when the whip roll moves forwardly, said return means to move the member from releasing to holding position when the warp roll moves rearwardly, and a hydraulic system connected to the brake means and controlled by the member to have the pressure therein increased to move the brake means to holding position when the member moves to holding position, and have the pressure therein reduced when the member moves to releasing position, whereupon the release means moves the brake means to' releasing position.

6. In a warp let-01f mechanism for a loom having a rotatable warp beam and a gear fixed with respect to and rotating with thebeam, a pinion meshing with the gear to turn when the warp beam turns and effective when held against rotation to prevent turning of the warp beam, brake means for the pinion, a hydraulic system connected to the brake means to control the amount of braking force exerted thereby on the pinion, a whip roll moved forwardly by the warp during the weaving operation when the warp beam is prevented from turning, weighted means tending normally to move the whip roll rearwardly, a controller for the hydraulic system to determine the fluid pressure Within said system,

controller actuator means by which the whipv roll when moving forwardly causes the controller to reduce the fluid pressure within said hydraulic system to a point which will permit the warp beam and pinion to rotate, and the weighted means effective during rearward motion of the whip roll to move the actuator means to cause the controller to increase the fluid pressure of the hydraulic system to a point which will cause the brake means to prevent rotation of the pinion and warp beam.

'7. In a warp let-off mechanism for a loom having a rotatable warp beam having a gear fixed with respect thereto and rotating therewith, a pinion meshing with the gear to turn when the war beam turns and efiective when held from turning to prevent rotation of the gear and warp beam, brake means for the pinion, a

hydraulic system connected to the brake means to control the amount of braking force exerted by said brake means on the pinion, a controller for the hydraulic system movable in one direction to decrease and in the opposite direction to increase the fluid pressure within said hydraulic system, controller actuator means to cause the whip roll when moving forwardly to move said controller in said one direction, means to move the whip roll rearwardly and move the actuator means to cause movement of the controller in said other direction, the increase in fluid pressure within the system being sufficient to cause the brake means to prevent rotation of the pinion when the whip roll reaches a given point in its rearward motion, and the decrease in pressure within the hydraulic system reaching a level insufficient to enable the brake means to prevent rotation of a pinion when the whip roll reaches a given position in the forward motion thereof.

8. In a warp let-off mechanism for a loom having a rotatable warp beam and a gear movin therewith and having also a whip roll movable forwardly by the warp during the weaving operationwhen the warp beam is prevented from rotating, the loom having return means to move the whip roll rearwardly due to lessening of the warp tension when the beam rotates to feed warp, a pinion meshing with the gear and tuming when the warp beam rotates and effective when prevented from turning to hold the gear and beam stationary, brake means for the pinion movable to holding position to prevent rotation of the pinion, release means to move the brake means to releasing position to permit rotation of the pinion and warp beam by the warp, and a hydraulic system connected to the brake means and controlled by the Whip roll and said return means, the whip roll when moving forwardly be- M ing operative to decrease the pressure Within said hydraulic system to permit the release means to move the brake means to releasing position with respect to said pinion, and said return means operative when the whip roll moves rearwardly to increase the pressure in said hydraulic system to overpower said release means and move the brake means to holding position with respect to said pinion.

9. In a warp let-off mechanism for a warp beam removably mounted on a loom, a gear secured to and rotating with the beam, a pinion supported under and meshing with the gear, hydraulic brake means to prevent rotatation of the inion, a hydraulic system connected to the brake means, a member cooperating with "the system and movable to holding position to cause the system to operate the brake and hold the pinion against rotation, and means to hold said member in said holding position to hold the inion against rotation when the warp beam is removed from the loom.

10. In a warp let-oiif mechanism for a loom having a removable war-p beam, a gear secured to the beam, a pinion supported under and meshing with the gear, a member movable to holding position, .a hydraulic brake system between the member and the pinion and operated by the member when the latter is in said holding position to prevent rotation of the pinion, and means to lock the member in holding position during removal of the warp beam to prevent rotation of the pinion when the gear rolls along the pinion during removal of the beam from the loom.

11. In a warp let-off mechanism for a loom having a warp beam, a gear secured to and rotatable with the warp beam, means to mount the beam removably on the loom, a pinion supported under and meshing with the gear, a hydraulic system including a brake member connected to the pinion and normally permitting rotation of the pinion, an operator for the system movable to holding position and when in said holding posit-ion acting on the system to cause the latter to prevent rotation of the pinion, and a lock to hold the operator in holding position and prevent turning of the pinion during removal of the warp beam.

12. In a warp let-oiT mechanism for a loom having a removable warp beam, a gear secured to and rotating with the beam, a pinion supported under and meshing with the gear, a hydraulic system including a brake for the pinion to control the latter, an operator for th system movable from holding or releasing position, the system permitting rotation of the pinion when the operator is in releasing position, and means to lock the operator in releasing position preparatory to removal of the beam from the loom, whereby the pinion turns freeiy without offering resistance to the gear as the beam is removed from the loom.

13. In a warp let-off mechanism for a loom having a removable warp beam, a gear secured to and rotating with the beam, a pinion supported under and meshing with the gear, a hydraulic system including a brake for the pinion to control the latter, an operator for the system movable either to holding or releasing position and when in holding position causing the system to act through the. brake and prevent rotation of the pinion, the system permitting rotation of the pinion when the operator is in releasing position, and means to lock the operator either in holding or releasing position depending upon whether it is desired to have the pinion held against rotation or free to rotate during removal of the warp beam.

14. A brake unit for a Warp beam having a gear secured thereto, said brake unit comprising support means, a shaft rotatabiy mounted on said support means, a pinion for the gear secured to said shaft, a drum mounted on the shaft and fixed with respect to the pinion, brake shoes for said drum pivoted to said support means, and a hydraulic cylinder mounted on said support means for operation of the brake shoes.

ARC'HIBALD J, HERARD, JR. 

